>>The mere problem is - there is no other available, scientific theory at the moment except evolution on this matter<<
Boy, you nailed it there. The problem is that this is a binary problem. There are two categories into which all theories fall:
1. A species, as it currently exists got there by accident.
2. A species, as it currently exitst, got there by being designed that way by "someone".
Everything falls into one of the two beliefs. The name for all beliefs that fall in to number one is "evolution". To many, studying number one is considered science and studying number two is anything but. I disagree with that position.
To put it bluntly, number one, as discussed by some proponents, is not always science and number two, as discussed by some proponents, is not always religion.
And believing something was designed does not slow down research. In fact, if a thing WAS designed, research based on that belief would be the most fruitful.
Here's proof: http://aeroweb.lucia.it/rap/RAFAQ/Tu-4.html
If you mean to suggest that evolution is random, as I understand your post, you should know that it isn't. While it may include random factors such as mutations, it is not random in other respects, such as natural selection.
Also, I disagree. I don't think the options are necessarily limited to two. There may be other theories out there - it's not exactly a good thing to derive dichotomies in science.
I don't understand how evolution is not always science. It is a scientific theory so I don't understand that. I agree that design is not always religion but the ID movement definitely is. By refusing to specify the designer such that the designer may be subject to falsification tests, it is impossible to falsify ID and thus, it is not science.
I don't know if it would slow down research or not. All I know is that ID proponents have remained, scientifically, static for the last couple of decades. If ID proponents can introduce a falsifiable hypothesis, then I and probably other scientists, would welcome it to scientific scrutiny.